Same thing for me, and it is not related to being in a clan or a public event. It happens to me everywhere I go and in everything I do, including story mode, crucible, adventures, and everything else. I am not in a clan, and it is not low FPS because I have a GTX 1070 and am running at 100 FPS. But still, I get little freezes/stuttering/whatever as often as every few seconds, making the game nearly unplayable. Haven't seen a game launched that was this buggy since Watch Dogs.